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Which is better, vitamin C or zinc?

Vitamin C…

It’s cold season and products that claim to prevent or significantly shorten colds are flying off the drugstore shelves.

As I emphasized in an earlier post, frequent hand washing is your best strategy to avoid a cold altogether.

Still, the advertisements for such products are both pervasive and persuasive But are they worth buying?

Vitamin C (1000mg) is the major ingredient of Airborne and Emergen-C. Both are made into fizzy drinks. Airborne also claims to have a “proprietary blend” of minerals and herbs, but it’s really about the vitamin C. The Food and Drug Administration (FDA) will not allow either to claim that they prevent colds; they can only state that they “boost” the immune system. The Emergen-C package actually has the following generic disclaimer:

This product is not intended to diagnose, treat, cure or prevent any disease. [my emphasis]

Airborne recommends up to 3000mg per day; Emergen-C advises no more than 4000mg per day.

The recommended daily allowance for vitamin C is about 80mg/day. An 8-ounce glass of orange juice has 97mg.

Doses larger than 2000mg/day can lead to kidney stones, heartburn, nausea and diarrhea.

Despite over 60 years of clinical studies, there is no definitive proof that large doses of vitamin C can either prevent or lessen the duration of a common cold. In a 2010 review of the available research, the Cochrane Reviews concluded that

the failure of vitamin C supplementation to reduce the incidence of colds in the general population indicates that routine prophylaxis is not justified.